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Effects of riociguat on right ventricular size and function in pulmonary arterial hypertension (RIVER II): a prospective, phase IV study

delete2026-07-28
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OA
AI
S
Satenik Harutyunova
J
Jonathan Heinz
N
Nicola Benjamin
L
Lena Brückner
F
Faruk Sehic
B
Benjamin Egenlauf
A
Andrea Salzano
A
Alberto M. Marra
E
Ekkehard Grünig
P
Panagiota Xanthouli *
DOI:10.1186/s12931-026-03843-8delete
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Abstract

Abstract

En 中文
Pulmonary arterial hypertension (PAH) is characterized by right ventricular (RV) pressure overload, dilatation and dysfunction, which are key prognostic determinants. While riociguat improves exercise capacity and hemodynamics, prospective data on reverse remodeling remain limited. This prospective, phase IV study evaluated the effects of riociguat on right-heart size, function, hemodynamics, exercise capacity and safety in PAH patients. Treatment-naïve or pretreated PAH patients were enrolled. Patients receiving phosphodiesterase-5 inhibitors (PDE5i) could be switched to riociguat upon clinical indication. The primary endpoint was the change in right atrial (RA) and RV area at 24 weeks. Secondary endpoints included additional echocardiographic, clinical, exercise, hemodynamic and laboratory parameters, as well as quality-of-life (QoL) and safety. Thirty patients (61.2 ± 14.5 years; 76.7% male; 24 PDE5i-pretreated) were enrolled. Marked right-heart dilatation and impaired RV function were prominent at baseline. At week 24, riociguat significantly reduced RA (Δ -3.17 ± 5.91 cm²; p = 0.006) and RV area (Δ -6.00 ± 3.80 cm²; p < 0.0001). Furthermore, RV-fractional area change, 6-minute walking distance and functional class improved significantly. In patients with invasive follow-up, cardiac index increased significantly, with favorable trends in further parameters. N-terminal pro-brain natriuretic peptide and QoL remained unchanged. The study terminated early following the decision by the supplier Merck/MSD; the termination was not safety related. Riociguat was generally well tolerated with no new safety concerns. Riociguat therapy resulted in a statistically significant improvement in right ventricular and atrial size and function with further improvements in exercise capacity and functional class. This prospective trial confirms the findings of previous retrospective studies and supports riociguat as an effective treatment option to improve RV geometry and performance. This trial was registered on clinicaltrials.gov with the ClinicalTrials.gov ID NCT04954742.
Keywords:
Pulmonary arterial hypertension
Riociguat
Right-heart size and function
Echocardiography

Journal

Respiratory Research cover
Respiratory Research
IF:
5
Papers:
803
Citations:
1.5W

Organization

U
University of Naples Federico II
Scholars:
4.6W
Papers: 3.6W
Citations: 51
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